Abstract:

A plasma arc tube display is fabricated by arranging a plurality of arc
tubes having fluorescent substance layers on the inside and filled with a
discharge gas, joining a front substrate and a rear substrate having
electrodes to both surfaces of these arranged arc tubes, and
interconnecting a plurality of plasma arc tube modules having frames
facing the rear substrate with the flexible front substrate interposed
therebetween to connect the electrodes installed on the front substrate
to each other. Since the plasma arc tube modules can be folded, the
plasma arc tube display can be easily transported even if it has a
large-sized screen.

Claims:

1. A plasma arc tube display device comprising:plural plasma arc tube
modules placed adjacent to one another, each plasma arc tube module
comprising arranged plural plasma arc tubes, a front-surface substrate
and a back-surface substrate each having electrodes, which are placed
respectively on front surfaces and back surfaces of the arranged plural
plasma arc tubes, and a back-surface frame placed on the back-surface
substrate at a side which does not face the plural plasma arc tubes,
andcoupling portions placed between the plural plasma arc tube modules,
for coupling the plural plasma arc tube modules to one another such that
they are pivotable with respect to one another.

2. The plasma arc tube display device according to claim 1, whereinthe
coupling portions comprisefolding-back portions of the front-surface
substrates which are folded toward the back-surface substrates, in the
respective plural plasma arc tube modules, at end portions of the plural
plasma arc tube modules which are adjacent to each other,bonding portions
for bonding the electrodes on the respective front-surface substrates to
one another, andbending portions which can be bent between the
folding-back portions and the bonding portions.

3. The plasma arc tube display device according to claim 2, whereinthe
respective front-surface substrates are secured to the respective
back-surface frames at the folding-back portions.

4. The plasma arc tube display device according to claim 1,
whereinchamfering is applied to an end surface of the back-surface frame
which is in contact with the front-surface substrate.

5. The plasma arc tube display device according to claim 1, whereinend
portions of the respective front-surface substrates in the plasma arc
tube module and the other plasma arc tube modules adjacent thereto are
partitioned into plural parts, the end portions partitioned into plural
parts are folded toward the back-surface substrates, and electrodes on
the respective end portions partitioned into the plural parts are bonded
to one another through the bonding portions.

6. The plasma arc tube display device according to claim 1, further
comprising fixing portions for fixing the respective back-surface frames
in the plasma arc tube module and the other plasma arc tube modules
adjacent thereto.

7. The plasma arc tube display device according to claim 6, whereinthe
fixing portions have pivot supporting portions which are coupled
respectively to the plasma arc tube module and the other plasma arc tube
modules adjacent thereto such that the plasma arc tube module and the
plasma arc tube modules adjacent thereto are pivotable.

8. The plasma arc tube display device according to claim 7, whereinthe
fixing portions have variable portions which extend and contract
distances among the pivot supporting portions and the plasma arc tube
module and the other plasma arc tube modules adjacent thereto, thereby
realizing a structure which enables folding up the plasma arc tube module
and the other plasma arc tube modules adjacent thereto.

9. The plasma arc tube display device according to claim 8, whereinthe
fixing portions have a structure for folding up the plasma arc tube
module and the other plasma arc tube modules adjacent thereto, such that
respective front surfaces of the plasma arc tube module and the other
plasma arc tube modules adjacent thereto are faced inwardly.

10. A plasma arc tube display device comprising:plural arc tube modules
each comprising a front-surface substrate which is provided on front
surfaces of plural plasma arc tubes and has plural pairs of electrodes
placed thereon in a direction orthogonal to a longitudinal direction of
the plasma arc tubes such that the pairs of electrodes are in contact
with the plasma arc tubes, a back-surface substrate which is provided on
back surfaces of the plural plasma arc tubes and has plural electrodes
placed thereon in a direction parallel to the longitudinal direction of
the plasma arc tubes such that the electrodes are in contact with the
plasma arc tubes, and a back-surface frame placed on the back-surface
substrate for supporting the plural plasma arc tubes,a relay driving
circuit having driving circuits adapted to apply a voltage to at least
one of the pairs of electrodes, the driving circuits being bonded to the
electrodes on the front-surface substrates which are placed on the front
surfaces of the plural plasma arc tubes and are folded toward the
back-surface substrates at end portions and to the electrodes on the
front-surface substrates which are placed on front surfaces of other
plasma arc modules adjacent to the plasma arc tube module and are folded
toward the back-surface substrates at the end portions, andcoupling
portions for coupling the plasma arc tube modules to the other plasma arc
tube module adjacent thereto.

11. The plasma arc tube display device according to claim 10, whereinthe
coupling portions have folding-back portions of the front-surface
substrates which are folded toward the back-surface substrates, in the
respective plural plasma arc tube modules, at end portions of the plural
plasma arc tube modules which are adjacent to each other,bonding portions
for bonding the electrodes on the respective front-surface substrates to
one another, andbending portions which can be bent between the
folding-back portions and the bonding portions.

12. The plasma arc tube display device according to claim 10, further
comprising fixing portions for fixing the respective back-surface frames
in the plasma arc tube module and the other plasma arc tube modules
adjacent thereto.

13. A plasma arc tube display device comprising:a front-surface substrate
which is provided on front surfaces of plural plasma arc tubes and has
plural pairs of electrodes placed thereon in a direction orthogonal to a
longitudinal direction of the plasma arc tubes such that the pairs of
electrodes are in contact with the plasma arc tubes, each of the pairs of
electrodes being constituted by a pair of a sustain electrode X and a
scan/sustain electrode Y;a back-surface substrate which is provided on
back surfaces of the plural plasma arc tubes and has plural address
electrodes placed thereon in a direction parallel to the longitudinal
direction of the plasma arc tubes such that the address electrodes are in
contact with the plasma arc tubes;a driving unit which performs
processing on signals from external devices, applies driving voltages to
the pairs of electrodes and the address electrodes, applies a driving
voltage to ones of the pairs of electrodes, in order to select cells
which are defined by the pairs of electrodes and the address electrodes
and are associated with light emission areas of fluorescent members, in
response to the signals, and applies a driving voltage to the pairs of
electrodes for causing the fluorescent members to emit light;a
back-surface frame which is placed on the back-surface substrate in a
plasma arc tube module for supporting the plasma arc tube module;bonding
portions for bonding the electrodes on the front-surface substrate which
is placed on a front surface of the plasma arc tube module and is folded
toward the back-surface substrate at end portions thereof and the
electrodes on the front-surface substrates which are placed on front
surfaces of other plasma arc tube modules adjacent to the plasma arc tube
module and are folded toward the back-surface substrates at end portions
to each other; andbending portions which can be bent between the bonding
portions and the end portions of the respective front-surface substrates
in the plasma arc tube module and the other plasma arc tube modules
adjacent thereto.

14. The plasma arc tube display device according to claim 13, further
comprising fixing portions for securing the respective back-surface
frames in the plasma arc tube module and the other plasma arc tube
modules adjacent thereto,wherein the fixing portions have pivot
supporting portions which are coupled respectively to the plasma arc tube
module and the other plasma arc tube modules adjacent thereto such that
the plasma arc tube module and the plasma arc tube modules adjacent
thereto are pivotable.

[0003]Each of the arc tubes has a hollow shape with a circular,
elliptical, or rectangular cross sectional shape, generally has an MgO
layer as a protective layer formed on an inner wall surface of a thin
tube with such a shape for protecting a glass surface used in the thin
tube from gas electrical discharge, further has a fluorescent layer
formed on the MgO layer and, further, confines an electrical discharge
gas formed from Ne and Xe gases mixed with each other, for example,
within a hollow space thereof. A plurality of such arc tubes fabricated
as described above are arranged such that sets of three arc tubes which
emit light of respective primary colors of RGB are repeatedly arranged,
in order to structure a display device capable of color image display. On
front surfaces of these arranged arc tubes which are display surfaces
thereof, display electrodes (sustain electrodes X and scan/sustain
electrodes Y) are placed in a direction orthogonal to the plasma arc
tubes, and address electrodes are provided on back surfaces thereof in a
longitudinal direction of the respective plasma arc tubes. The display
electrodes are structured by laminating transparent electrodes formed on
a transparent resin film for ensuring transmission of emitted light and
bus electrodes made of a metal such as copper as conductors, for example,
for ensuring conductivity thereof.

[0004]Such a display device having the aforementioned structure is capable
of realizing a self-light-emission type display with a diagonal distance
of, for example, 100 inches, with the arranged plural plasma arc tubes.
Further, since the plasma arc tubes are thin tubes, and the MgO layer and
the fluorescent layer are formed inside the thin tubes, it is possible to
fabricate a large-sized display device with small-scale fabrication
equipment for fabricating these plasma arc tubes. This enables
fabrication of display devices with lower costs.

[0005]As described above, such a display device employing plasma arc tubes
has characteristics which other display devices cannot have, but requires
attachment of electrode films having electrodes formed on large-area
films to the front surfaces and the back surfaces of the arranged plasma
arc tubes, in creating a large-area display device having a plurality of
arranged plasma arc tubes. Accordingly, fabrication of the large-area
electrode films and attachment of the electrode films to the arranged
plural plasma arc tubes with high accuracy have induced a problem of
increases of costs. Further, in conveying the large-screen display
device, there has been a need for a large-sized packaging device, in
order to prevent the display surface and the like from experiencing
shocks and, furthermore, there has been a problem of difficulty of
handling thereof.

[0008]It is an object of the present invention to overcome an increase of
a cost due to fabrication of the aforementioned large-area electrode
films and attachment of the electrode films to the arc tubes with high
accuracy and also to facilitate conveyance and handling of the
large-screen plasma arc tube display device.

Means for Solving the Problems

[0009]In order to overcome the aforementioned problem, a plasma arc tube
display device according to one aspect of the present invention is
characterized in that it includes plural plasma arc tube modules placed
adjacent to one another, each plasma arc tube module including arranged
plural plasma arc tubes, a front-surface substrate and a back-surface
substrate each having electrodes, which are placed respectively on front
surfaces and back surfaces of the arranged plural plasma arc tubes, and a
back-surface frame placed on the back-surface substrate at a side which
does not face to the plural plasma arc tubes, and coupling portions
placed between the respective adjacent plasma arc tube modules, out of
the plural plasma arc tube modules, for coupling the plural plasma arc
tube modules to one another such that they are pivotable with respect to
one another. The coupling portions preferably include folding-back
portions of the front-surface substrates which are folded toward the
back-surface substrates, in the respective plural plasma arc tube
modules, at end portions of the plural plasma arc tube modules which are
adjacent to each other, bonding portions for bonding the electrodes on
the respective front-surface substrates to one another, and bending
portions which can be bent between the folding-back portions and the
bonding portions. Further, the plasma arc tubes confine an electrical
discharge gas and a fluorescent member.

[0010]Further, the respective front-surface substrates can be secured to
the respective back-surface frames at the folding-back portions. Also,
preferably, chamfering is applied to respective end surfaces of the
back-surface frames which are in contact with the front-surface
substrates. Furthermore, preferably, the end portions of the respective
front-surface substrates in the plasma arc tube module and the other
plasma arc tube modules adjacent thereto are partitioned into plural
parts, the end portions partitioned into plural parts are folded toward
the back-surface substrates, and electrodes on the respective end
portions partitioned into the plural parts are bonded to one another
through the bonding portions. Also, there are provided fixing portions
for fixing the respective back-surface frames in the plasma arc tube
module and the other plasma arc tube modules adjacent thereto.

[0011]Further, the plasma arc tube display device according to another
aspect of the present invention is characterized in that it includes
pivot supporting portions which are coupled respectively to the plasma
arc tube module and the other plasma arc tube modules adjacent thereto
such that the plasma arc tube module and the plasma arc tube modules
adjacent thereto are pivotable.

[0012]Further, a plasma arc tube display device according to another
aspect of the present invention is characterized in that it includes
plural arc tube modules each including a front-surface substrate which is
provided on front surfaces of plural plasma arc tubes and has plural
pairs of electrodes placed thereon in a direction orthogonal to a
longitudinal direction of the plasma arc tubes such that the pairs of
electrodes are in contact with the plasma arc tubes, a back-surface
substrate which is provided on back surfaces of the plural plasma arc
tubes and has plural electrodes placed thereon in a direction parallel to
the longitudinal direction of the plasma arc tubes such that the
electrodes are in contact with the plasma arc tubes, and a back-surface
frame placed on the back-surface substrate for supporting the plural
plasma arc tubes, a relay driving circuit having driving circuits adapted
to apply a voltage to at least one of the pairs of electrodes, the
driving circuits being bonded to the electrodes on the front-surface
substrates which are placed on the front surfaces of the plural plasma
arc tubes and are folded toward the back-surface substrates at end
portions thereof and to the electrodes on the front-surface substrates
which are placed on front surfaces of other plasma arc modules adjacent
to the plasma arc tube modules and are folded toward the back-surface
substrates at the end portions, and coupling portions for coupling the
plasma arc tube module to the other plasma arc tube modules adjacent
thereto.

[0013]In this case, the aforementioned coupling portions can have
folding-back portions of the front-surface substrates which are folded
toward the back-surface substrates, in the respective plural plasma arc
tube modules, at the end portions of the plural plasma arc tube modules
which are adjacent to each other, bonding portions for bonding the
electrodes on the respective front-surface substrates to one another, and
bending portions which can be bent between the folding-back portions and
the bonding portions.

[0014]A plasma arc tube display device according to another aspect of the
present invention is characterized in that it includes a front-surface
substrate which is provided on front surfaces of plural plasma arc tubes
and has plural pairs of electrodes placed thereon in a direction
orthogonal to a longitudinal direction of the plasma arc tubes such that
the pairs of electrodes are in contact with the plasma arc tubes, each
pair of electrodes being constituted by a pair of a sustain electrode X
and a scan/sustain electrode Y; a back-surface substrate which is
provided on back surfaces of the plural plasma arc tubes and has plural
address electrodes placed thereon in a direction parallel to the
longitudinal direction of the plasma arc tubes such that the address
electrodes are in contact with the plasma arc tubes; a driving unit which
performs processing on signals from external devices, applies driving
voltages to the pairs of electrodes and the address electrodes, applies a
driving voltage to ones of the pairs of electrodes, in order to select
cells which are defined by the pairs of electrodes and the address
electrodes and are associated with light emission areas of fluorescent
members, in response to the signals, and applies a driving voltage to the
pairs of electrodes for causing the fluorescent members to emit light; a
back-surface frame which is placed on the back-surface substrate in a
plasma arc tube module for supporting the plasma arc tube module; bonding
portions for bonding the electrodes on the front-surface substrate which
is placed on the front surface of the plasma arc tube module and is
folded toward the back-surface substrate at end portions and the
electrodes on the front-surface substrates which are placed on front
surfaces of other plasma arc tube modules adjacent to the plasma arc tube
module and are folded toward the back-surface substrates at end portions
to each other; and bending portions which can be bent between the bonding
portions and the end portions of the respective front-surface substrates
in the plasma arc tube module and the other plasma arc tube modules
adjacent thereto.

[0015]In this case, preferably, there are provided fixing portions for
securing the respective back-surface frames in the plasma arc tube module
and the other plasma arc tube modules adjacent thereto, and the fixing
portions have pivot supporting portions which are coupled respectively to
the plasma arc tube module and the other plasma arc tube modules adjacent
thereto such that the plasma arc tube module and the plasma arc tube
modules adjacent thereto are pivotable.

EFFECTS OF THE INVENTION

[0016]Since there are provided plural plasma arc tube modules including
arranged plural plasma arc tubes, front-surface substrates having pairs
of display electrodes provided on the front surfaces of the arranged
plasma arc tubes and back-surface substrates having address electrodes
provided on the back surfaces thereof, the respective plasma arc tube
modules are connected to one another through the front-surface substrates
having flexibility for relaying the electrodes provided on the
front-surface substrates, it is possible to realize a plasma arc tube
display device which enables reducing areas of the front-surface
substrates and the back-surface substrates, folding up the plasma arc
tube modules and cost reduction and also facilitates conveyance thereof
even if it has a large sized screen.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a view illustrating a general outline of a plasma arc tube
display device.

[0018]FIG. 2 is a schematic view illustrating main parts of the plasma arc
tube display device.

[0019]FIG. 3 is a schematic view illustrating main parts of connections
between plasma arc tube modules.

[0020]FIG. 4 is a schematic view of an electrode relay board in FIG. 3.

[0021]FIG. 5 is a view illustrating another example of the electrode relay
board illustrated in FIG. 4.

[0022]FIG. 6 is a schematic view of a back-surface frame.

[0023]FIG. 7 is a schematic view illustrating another example of a first
embodiment.

[0031]Hereinafter, preferred embodiments for carrying out the present
invention will be described. In the present embodiments, there will be
mainly described a case where arc tubes have a substantially rectangular
cross sectional shape (with a longer side equal to 1 mm, a shorter side
equal to 0.5 mm, and a thickness equal to 100 micrometers), but the cross
sectional shape can be another shape such as a circular shape or an
elliptical shape. Further, even in a case of rectangular cross sectional
areas, dimensions are not limited to the aforementioned dimensions.

First Embodiment

[0032]FIG. 1 illustrates a schematic view illustrating a plasma arc tube
display device 200 according to the present invention which employs two
plasma arc tube modules 10, when this plasma arc tube display device 200
is viewed at a back surface thereof. Back-surface frames 40 provided on
back-surface substrates 30 in the respective plasma arc tube modules 10
are secured through fixture screws 100 (three screws in the figure), and
pairs of display electrodes (which will be described later in detail)
provided on front-surface substrates 20 in the respective plasma arc tube
modules 10 are electrically connected to each other through an electrode
relay board 50. Further, the back-surface substrates 30 also have
redundant portions protruding from the back-surface frames 40, in order
to be connected to circuits which are not illustrated, similarly to the
front-surface substrates 20, but the redundant portions are not
illustrated, for clarification of illustration of main parts of the
present invention.

[0033]FIG. 2 is a perspective view illustrating main parts of the plasma
arc tube modules 10 used in the plasma arc tube display device according
to the present invention, illustrating the vicinity of the plasma arc
tube modules 10 which are adjacent to each other. The plasma arc tube
display device 200 employs the plural plasma arc tube modules 10 to
constitute a display screen.

[0034]Plasma arc tubes 1 constituting the plasma arc tube modules 10 have
a rectangular-shaped cross section, have a protective layer (for example,
an MgO layer, which is not illustrated) formed on tubular walls thereof
and further have a fluorescent layer 2 placed thereon. Further, an
electrical discharge gas (for example, a gas formed from Xe gas and Ne
gas which are mixed with each other, which is not illustrated) is
enclosed therein, and the plasma arc tubes are sealed at opposite end
portions. A plurality of such plasma arc tubes 1 are arranged, and the
front-surface substrates 20 are attached to front surfaces of the plasma
arc tubes 1 and the back-surface substrates 30 are attached to back
surfaces of the plasma arc tubes 1, through a transparent adhesive
member, preferably an epoxy resin or a photo-curing resin. Pairs of
display electrodes 24 are formed on base films 22 in the front-surface
substrate 20 at the surfaces contacting with the plasma arc tubes 1. The
base films 22 are made of transparent films for facilitating transmission
of light emitted from the plasma arc tubes 1 therethrough and, in the
first embodiment, are made of films with a thickness of 120 micrometers
which are made of poly ethylene terephthalate (PET). A material of the
base films 22 is not limited to PET, and can be any material having
flexibility for facilitating attachment to the plasma arc tubes 1, having
transparency and also enabling formation of transparent electrodes (for
example, ITO films and NESA films), metal electrodes, metal mesh-type
electrodes and the like which constitute the pairs of display electrodes
24 formed on the base films 22. Further, the thickness thereof is not
limited to 120 micrometers.

[0035]Address electrodes 34 are formed on base films 32 in the
back-surface substrates 30. The address electrodes 34 are placed through
copper plating to have a width of 200 micrometers and a thickness of 20
micrometers, such that they are in contact with lower portions of the
plasma arc tubes 1 along a longitudinal direction of the respective
plasma arc tubes 1. Also, the address electrodes 34 can be formed from a
conductive paste through print processing, as well as through plating. It
is also possible to employ a method for forming address electrodes 34
with a desired shape, by applying etching to a metal layer such as a
copper layer attached to the base films 32.

[0036]The fluorescent layers 2 formed in the plasma arc tubes 1 are made
of fluorescent members corresponding to colors of light emitted from the
plasma arc tubes 1. For example, the plasma arc tube 1 which emits red
light, the plasma arc tube 1 which emits green light, and the plasma arc
tube 1 which emits blue light are arranged, in an order mentioned above.

[0037]The back-surface frame 40 is mounted to one surface of the
back-surface substrate 30. The back-surface frame 40 and the back-surface
substrate 30 can be mounted to each other by attaching them together on
the entire surfaces or by partially attaching them to each other.
Further, a curved portion 42 is provided or chamfering is applied to an
end portion of the back-surface frame 40 near a portion of the plasma arc
tube module 10 which is in contact with the adjacent plasma arc tube
module 10, so that the back-surface frame 40 is processed into an L
shape.

[0039]As described above, the plasma arc tube modules 10 are connected to
each other through the electrode relay board 50, and the base films 22 in
the front-surface substrates 20 are formed from PET or the like which has
flexibility, which allows the plasma arc tube modules 10 to be folded
about the vicinity of the electrode relay board 50, as illustrated in
FIG. 3. More specifically, end portions of the respective plasma arc tube
modules 10 are folded at the folding-back portions 26 toward the
back-surface substrates 30 and are secured to the frames, near the curved
portions 42 of the back-surface frames 40, through an epoxy resin or the
like, to form fixing portions 44. The respective front-surface substrates
20 are not secured to other members, up to the vicinity of the electrode
relay board 50 beyond the fixed portions 44, thereby forming bending
portions 28 which can be bent due to flexibility of the base films 22.

[0040]As described above, the plasma arc tube modules 10 are connected to
each other, through the base films 22 having flexibility, to form
coupling portions therebetween, which allows the plasma arc tube modules
10 to be folded with respect to each other, as illustrated in FIG. 3.

[0041]Next, with reference to FIG. 4A, there will be described, in detail,
the vicinity of the electrode relay board 50. The electrode relay board
50 is formed from a substrate 52 made of PET or epoxy resin and a
conductive relay pattern 54 formed on one surface of the substrate 52,
and this relay pattern 54 electrically connects pairs of display
electrodes 24A on one of the plasma arc tube modules 10 to pairs of
display electrodes 24B on the other plasma arc tube module 10. The pairs
of display electrodes 24B are formed from a conductive pattern extending
from the back surface of the front-surface substrate 20 to the front
surface thereof through an end portion of the base film 22 in the
front-substrate substrate 20, as illustrated in FIG. 4A. The pairs of
display electrodes 24A and 24B and the relay pattern 54 on the electrode
relay board 50 are coupled to each other, through thermo compression
bonding, for example.

[0042]A structure of the pairs of display electrodes 24B is such that the
display electrodes 24 and the display electrodes 24B are connected to
each other via a through hole penetrating through the base film 22, and
the pairs of display electrodes 24A and the pairs of display electrodes
24B on the respective front-surface substrates 20 are electrically
connected to each other through the electrode relay board 50. The pairs
of display electrodes 24A can also be provided with a through hole, and
the pairs of display electrodes 24A and 24B on the respective
front-surface substrates 20 can be directly electrically connected to
each other, through thermo compression bonding, without using the
electrode replay board 50.

[0043]Further, FIG. 5 illustrates a structure of another connection of the
pairs of display electrodes 24. FIG. 5 illustrates a relaying method
using a connector 60, instead of the electrode relay board 50, wherein an
electrically-conductive conductor 62 for connecting the pairs of display
electrodes 24 in the respective plasma arc tube modules 10 to each other
is provided on an inner surface of the connector 60. This conductor 62 is
in contact with the pairs of display electrodes 24 on the respective
front-surface substrates 20, thereby enabling establishing electrical
conduction between the corresponding pairs of display electrodes 24 on
the respective adjacent front-surface substrates 20. This method offers
an advantage of eliminating necessity of providing pairs of display
electrodes 24 on the opposite surfaces of the front-surface substrates
20. Further, it is also possible to employ a method of connecting the
respective electrodes to one another through conductors, a method of
connecting them through a flexible print board, and the like, in order to
establish electrical conduction between the pairs of display electrodes
24.

[0044]Next, with reference to FIG. 6, the back-surface frames 40 will be
described in detail. A material of the back-surface frames 40 may be any
hard material, but is preferably an aluminum material since it is
lightweight, has excellent heat conductivity and excellent workability.
FIG. 6 is a main-part schematic view of a back-surface frame made of an
aluminum plate, illustrating the vicinity of the curved portion 42 of
FIG. 2. There are provided vent holes 46, in order to reduce the weight
of the back-surface frame 40 and improve air permeability thereof, at a
portion in contact with the back-surface substrate 30 in the plasma arc
tube module 10, and there are further provided holes 48 in the L-shaped
portion near the curved portion 42. The holes 48 are for securing,
through screws or the like, the L-shaped portions of the opposing
back-surface frames 40 in the adjacent plasma arc tube modules 10 to each
other.

[0045]FIG. 7 illustrates another example of the plasma arc tube display
device 200 according to the aforementioned first embodiment. The plasma
arc tube display device 200 illustrated in FIG. 7 employs back-surface
frames 40A, instead of the back-surface frames 40 illustrated in FIG. 1.
The back-surface frames 40A are structured to be placed only near a
connection portion between the plasma arc tube modules 10 and offer an
advantage of reduction of the weight of the plasma arc tube display
device 200.

[0046]In the plasma arc tube display device 200 according to the first
embodiment, the respective front-surface substrates 20 are folded toward
the back-surface substrates 30, between the plasma arc tube modules 10,
and folded portions are provided with the bending portions 28 at which
the respective front-surface substrates 20 can be bent. Accordingly, even
if the plasma arc tube display device 200 has a large-sized display
screen, it is possible to fold up the plasma arc tube modules 10, thereby
facilitating handling thereof, during conveyance. Further, it is possible
to create the individual small-sized plasma arc tube modules 10 and then
assemble the plural plasma arc tube modules 10 to create the plasma arc
tube display devices 200, which enables reduction of the sizes of the
front-surface substrates 20 and the back-surface substrates 30 and also
enables replacement of only plasma arc tube modules 10 which have been
flawed, thereby offering an advantage of increase of a fabrication yield.

Second Embodiment

[0047]Next, a second embodiment will be described with reference to FIG.
8. In the second embodiment, components having the same functions as
those in the first embodiment are designated by the same reference
symbols. The second embodiment is different from the first embodiment, in
that a plasma arc tube display device 210 according to the second
embodiment has pivot supporting portions constituted by fixing portions
320 secured to back-surface frames 40 and arms 300 mounted to the fixing
portions 320 pivotably about shafts 310. The two arms 300 are allowed to
pivot about the respective shafts 310, thereby allowing the plasma arc
tube modules 10 to pivot with respect to each other. Accordingly, the
plasma arc tube modules 10 are connected to each other through connection
means which have the arms 300 and are capable of pivotably supporting
them, which can maintain a positional relationship between the plasma arc
tube modules 10 more firmly than in the plasma arc tube display device
200 according to the first embodiment which is adapted such that the
plasma arc tube modules 10 are connected to each other through only the
electrode relay board 50. This can reduce external forces applied to the
electrode relay board 50, thereby improving durability of the plasma arc
tube display device 210 during conveyance.

[0048]Further, it is preferable to place the aforementioned two connection
means employing the arms 300 at positions outside of a width W of the
electrode relay board 50. By placing the connection means in this manner,
the connection means and the electrode relay board 50 are prevented from
coming into contact with each other, when the plasma arc tube modules 10
are folded up.

[0049]Further, the plasma arc tube display device 210 has electrode
deriving portions 215 for connecting the front-surface substrates 20 to
circuits and the like which are not illustrated, wherein the electrode
deriving portions 215 are shaped to be partitioned into plural parts.
This shape is adaptable to the front-surface substrates 20 according to
the first embodiment, and the partitioned electrode deriving portions 215
offer an advantage of enabling mounting the respective parts
individually, thereby alleviating deformation of the front-surface
substrates 215.

[0050]FIG. 9 illustrates another example of the second embodiment. A
plasma arc tube display device 220 illustrated in FIG. 9 is the same as
the plasma arc tube display device 210 in that arms 300 are mounted to
fixing portions 320 secured to the back-surface frames 40 pivotably about
shafts 310, but is different from the plasma arc tube display device 210
in that the number of the connection means employing the arms is
increased to 4 and, also, is different therefrom in that the number of
the electrode relay boards 50 used therein is more than one (3 electrode
relay boards, in the figure). Since the plasma arc tube display device
220 has an increased number of the connection means, it is possible to
further reduce external forces applied to the electrode relay boards 50,
thereby improving durability of the plasma arc tube display device 220
during conveyance. Further, since the plural electrode relay boards 50
are employed, it is possible to facilitate positioning of the relay
patterns 54 (see FIG. 4A on the electrode relay boards 50 and the pairs
of display electrodes 24 on the front-surface substrates 20, thereby
improving efficiency of mounting operations.

[0051]FIG. 10A and FIG. 10B illustrate the shape of the plasma arc tube
display device 210 or 220 according to the aforementioned second
embodiment, when it is folded up. FIG. 10A illustrates a state where it
is folded up such that the back surfaces of the plasma arc tube modules
10 are faced outwardly, and FIG. 10B illustrates a state where it is
folded up such that the front surfaces of the plasma arc tube modules 10
are faced outwardly. Since the connection means employing the bending
portions 28 are employed between the respective plasma arc tube modules
10, it is possible to fold them up as illustrated in the figures.

[0052]While, in the first and second embodiments, there have been
described a case where the two plasma arc tube modules 10 are used, FIG.
11 illustrates an example of a plasma arc tube display device 230
employing four plasma arc tube modules 10. The plasma arc tube display
device 230 employs connection means employing arms as in the second
embodiment, but they are not illustrated in FIG. 11 for clarification of
illustration in the figure. Further, FIG. 12 illustrates a state where
the plasma arc tube display device 230 is folded up. FIG. 12 illustrates
that the plasma arc tube display device 230 according to the present
invention can be folded up, even though four plasma arc tube modules 10
are used, by elongating the bending portions 28 between the plasma arc
tube modules 10 which form outermost surfaces in the folded-up state.

Third Embodiment

[0053]FIG. 13 is a view illustrating connection between the plasma arc
tube display device 200, 210, 220 or 230 described in the first and
second embodiments and peripheral circuits. FIG. 13 illustrates
connection between the plasma arc tube display device 200 and the
peripheral circuits, but the plasma arc tube display devices 210, 220 and
230 can be employed, instead of the plasma arc tube display device 200.

[0054]A driving unit 500 is connected to the plasma arc tube display
device 200. In the present embodiment, the pairs of display electrodes 24
extend in the direction of rows in the display screen, and each pair of
display electrodes 24 is constituted by a pair of a scan/sustain
electrode Y410 and a sustain electrode X400. Areas at intersections of
the pairs of display electrodes 24 and the address electrodes 34 are
referred to as cells. In selecting cells to be caused to emit light
through electrical discharge between the pairs of display electrodes 24,
out of the cells, the scan/sustain electrodes Y410 are used as scan
electrodes for use in selecting cells on a row-by-row basis. The address
electrodes 34 extend in the direction of columns and are used as
electrodes for selecting cells on a column-by-column basis. The driving
unit 500 includes a controller 512, a data processing circuit 514, an X
driver 516, a scan driver 518, a Y common driver 520, an address driver
522, a power supply circuit which is not illustrated, and the like. An
externals device such as a TV tuner or a computer inputs, to the driving
unit 500, field data DF indicative of luminance levels (tone levels)
(luminance levels for respective colors of R, G and B in a case of color
display), on a pixel-by-pixel basis, along with various types of
synchronization signals. The field data DF is temporarily stored in a
frame memory 524 in the data processing circuit 514, then is subjected to
processing required for tone display, then is stored in the frame memory
524 and is transferred to an address driver 222 at proper timing.

[0055]The X driver 516 applies a driving voltage to all the sustain
electrodes X400. The scan driver 518 applies a driving voltage to the
respective scan/sustain electrodes Y410 individually, in selecting cells.
The Y common driver 520 applies a driving voltage to all the scan/sustain
electrodes Y410 concurrently, in maintaining lighting of the selected
cells.

[0056]FIG. 14 schematically illustrates a positional relationship among
the address driver 522, the X driver 516, the scan driver 518 and the Y
common driver 520 for driving the scan/sustain electrodes Y410 (the scan
driver 518 and the Y common driver 520 are comprehensively referred to as
a scan/sustain electrode Y driver 550) which have been described above,
and the plasma arc tube display device 200. FIG. 14 is a view
illustrating the plasma arc tube display device 200 at the back surface
thereof, wherein the same components as those in the first and second
embodiments are designated by the same reference symbols. In the plasma
arc tube display device 200 illustrated in FIG. 14, the scan/sustain
electrode Y driver 550 is placed on the electrode relay board 50 used in
the first and second embodiments. Since the scan/sustain electrode Y
driver 550 is placed at the center portion of the plasma arc tube display
device 200 as described above, the scan/sustain electrodes Y410
practically has a length half that in a case where the scan/sustain
electrode Y driver 550 is placed on the front-surface substrates 20,
thereby reducing an influence of voltage drop across the scan/sustain
electrodes Y410.

INDUSTRIAL APPLICABILITY

[0057]Plasma arc tube modules including arranged plural arc tubes having
fluorescent layers placed inside thereof, front-surface substrates and
back-surface substrates which are provided with electrodes and are
attached to opposite surfaces of these arranged arc tubes, and frames
provided on the back-surface substrates are connected to each other
through the front-surface substrates having flexibility for relaying the
electrodes provided on the front-surface substrates. This can realize a
plasma arc tube display device which enables folding up plasma arc tube
modules, thereby facilitating conveyance even if it has a large-sized
screen.